The goal of this R34 grant application is to develop and pilot-test a best practice model for the psychosocial treatment of obsessive-compulsive disorder (OCD), a chronic, debilitating, and costly psychiatric illness. Currently the psychosocial treatment of choice for OCD is cognitive-behavioral therapy (CBT) incorporating exposure with ritual prevention (EX/RP). Despite CBT's demonstrated efficacy, this treatment is largely inaccessible, time consuming, labor intensive, and expensive. Thus the "real world" effectiveness of the most validated psychosocial treatment for OCD is limited. This application will develop and test a novel treatment approach to delivering CBT (i.e., stepped care) in an attempt to increase the accessibility and cost-effectiveness of this treatment. In the CBT stepped care program, patients are first provided with a less expensive, less intrusive, and more accessible option that resembles quality community care (i.e., self-administered EX/RP combined with counseling to address medication issues, life stress, and motivational enhancement). Patients who fail to respond to this initial treatment progress to a more intensive treatment (i.e., therapist-administered EX/RP). The primary specific aims of this application are to 1) develop a stepped care protocol, 2) obtain iterative feedback from patients, study clinicians, and expert consultants to revise the protocol, and 3) obtain preliminary pilot data estimating an effect size that will be used in a power analysis for an R01 grant application. These aims will be accomplished in 1) an initial small open trial of the stepped care program that will provide data upon which to revise the manual, and 2) a small randomized controlled trial comparing effectiveness and cost of the revised stepped care protocol with "gold standard" immediate CBT. Stepped care is an innovative treatment approach that has the potential to greatly improve the accessibility and cost-effectiveness of care for patients with OCD. However, because of the novelty of this approach extensive protocol development and pilot research via this R34 application is needed before the program can be truly operational. [unreadable] [unreadable]